Covid Pandemic Effects on the Physical Fitness of Primary School Children: Results of the German EMOTIKON Project

Sports Medicine - Open

Table 6 Fixed effect estimates, standard errors and z-values of the LMM for OTK children

Source of variance	Fixed-effect estimate	Standard error	z-value
Grand mean (intercept)	0.433	0.054	7.98
Physical fitness component
ECS versus LUB	0.079	0.058	1.37
EC versus S	− 0.111	0.076	− 1.46
E versus C	0.268	0.095	2.81
L versus U	0.133	0.097	1.38
U versus B	− 0.356	0.110	− 3.24
Covid comparison (2016–2019 versus 2020–2022) nested within physical fitness components
Endurance: Covid	− 0.038	0.014	− 2.82
Coordination: Covid	− 0.024	0.014	− 1.75
Speed: Covid	− 0.008	0.013	− 0.57
PowerLOW: Covid	− 0.018	0.014	− 1.28
PowerUP: Covid	− 0.027	0.013	− 2.05
Balance: Covid	− 0.039	0.013	− 3.02
Age (linear) nested within physical fitness components
Endurance: a1	− 0.737	0.187	− 3.94
Coordination: a1	− 1.436	0.187	− 7.70
Speed: a1	− 0.793	0.185	− 4.28
PowerLOW: a1	− 1.254	0.193	− 6.51
PowerUP: a1	− 1.594	0.184	− 8.67
Balance: a1	− 0.695	0.175	− 3.98
Age (quadratic) nested within physical fitness components
Endurance: a2	0.206	0.097	2.12
Coordination: a2	0.507	0.097	5.25
Speed: a2	0.229	0.096	2.39
PowerLOW: a2	0.433	0.100	4.34
PowerUP: a2	0.643	0.095	6.74
Balance: a2	0.228	0.091	2.51
Sex nested within physical fitness components
Endurance: Sex	− 0.038	0.013	− 3.06
Coordination: Sex	0.051	0.013	4.08
Speed: Sex	0.018	0.012	1.46
PowerLOW: Sex	0.070	0.013	5.45
PowerUP: Sex	0.051	0.012	4.14
Balance: Sex	0.060	0.012	5.12

Physical fitness contrasts: ECS versus LUB = endurance, coordination, and speed versus powerLOW, powerUP, and balance. EC versus S = endurance and coordination versus speed. E versus C = endurance versus coordination. L versus U = powerLOW versus powerUP. U versus B = powerUP versus balance. Covid = Comparison of cohorts 2016–2019 with cohorts 2020–2022. Endurance = cardiorespiratory endurance (i.e., 6-min run test), coordination = star-run test, speed = 20-m linear sprint test, powerLOW = lower limbs muscle power (i.e., standing long jump test), powerUP = upper limbs muscle power (i.e., ball-push test), Balance = static balance (i.e., one-legged-stance test with eyes closed). Bold = |z| > 2.0, linear mixed model random factors: schools (514) and children (27,383), observations = 157,751. For estimates of variance components and correlation parameters, see Table 7